Osmotic devices for delivering an active agent to an environment of use are known to the prior art in U.S. Pat. Nos. 3,760,984 and 3,845,770. The devices disclosed in these patents comprise a wall formed of a material permeable to an external fluid and impermeable to agent with the wall surrounding a compartment containing an agent and having a passageway for dispensing the agent. Generally, these devices are remarkably effective for delivering an agent that is either soluble in the fluid and exhibits an osmotic pressure gradient across the wall against the fluid or for delivering an agent that has limited solubility in the fluid and is admixed with an osmotically effective compound soluble in the fluid that exhibits an osmotic pressure gradient against the fluid. The devices release agent by fluid being continuously imbibed through the wall into the compartment at a rate determined by the permeability of the wall and the osmotic pressure gradient across the wall to correspondingly continuously produce a solution of soluble agent or a solution of soluble compound containing agent which solution in either operation is dispensed from the device. While the above devices represent a significant and pioneer advancement in the art, there is an occasional application for dispensing an agent where a larger volume flow could be used than can be obtained with an osmotic system. For example, if the agent is practically insoluble in the external fluid, a larger volume of flow could advantageously be used for substantially preventing the agent from settling in the compartment and for dispensing agent from the device.